Transmission



1949. w. A. HASBANY 2,478,869

TRANSMIS S ION Original Filed June 21, 1946 ATTORNEYS Patented Aug. 9,1949 2,478,869 j TRANSMISSION Woodrow A. Hasbany, South Bend, Ind.,asaignor to The Studebaker Corporation, South Bend, Ind., acorporationot Delaware Original application June 21, 1946, Serial No.678,449. Divided and this application July 10, 1948, Serial No. 38,023

My present invention relates to an improvement in transmissions, andmore particularly to transmissions of the planetary or epicyclic geartype providing a plurality of gear ratios for forward drive and reversedrive.

My present application is a division of my application, Serial No.678,449, filed June 21, 1946.

Planetary gear mechanisms have come into use in constructing automaticor semi-automatic transmissions for automotive vehicles largely becauseof the ease with which they may be controlled to effect changes in gearratio. These automatic or semi-automatic transmissions usually comprisea fluid torque convert/or unit which, as is known, provide infinitelyvariable torque multiplication automatically, and which when used inconjunction with a planetary gear mechanism provides a form oftransmission particularly adaptable for use in obtaining desired forwardgear ratios for an automotive vehicle. In such types of transmissions ithas been proposed to provide a second planetary or epicyclic gearmechanism which is adapted to be actuated to provide for reverse drive.For example, a pair of planetary gear mechanisms may be arranged so thatone of the planetary gear mechanisms provides either ratio or directforward drive therethrough, when the second of the planetary gearmechanisms is locked up, and which latter planetary gear mechanism whenone of the elements thereof is caused to be held against rotation, isadapted to effect a reverse drive.

In the co-pending application of Harold E. Churchill, Paul V. Haigh andHarold O. Zander, Serial No. 644,828, filed February 1, 1946, there isdisclosed a transmission of a type last referred to. In the transmissionof that application a planetary gear mechanism is provided for efiectingreverse drive which has associated therewith positive jaw clutch andbrake means for clutching two of the elements together for conjointrotation for forward drive and for braking of one of the elements of themechanism to efi'ect reverse drive. However, it is found that theselective actuation of a planetary gear mechanism as by positive jawclutch and brake means to effect forward or reverse drive therethroughis not entirely satisfactory in that it is difficult to engage anddisengage the positive jaw clutch and brake I 6 Claims. (0]. 74-763)arranged with respect to each other so that one of the planetary gearmechanisms is adapted to be controlled to provide selected forward driveratios with another of the planetary gear mechanisms being adapted to becontrolled to efiect reverse drive.

A further object of my invention is to provide an arrangement of a pairof planetary gear mechanisms each comprising three elements, namely, asun gear, planet pinion means, and a ring gear, in which a common memberforms one ofthe elements of each of the planetary gear mechanisms andwith suitable brake and clutch means being associated with the planetarygear mechanisms operable for effecting selected forward drive ratiostherethrough and for effecting reverse drive. I

A still further object is to provide a transmismission as aforesaidhaving drive and driven shafts in which the pair of planetary gearmechanisms each have one of the elements thereof formed as acommonintegral member extending therebetween with a pair of the elementsof one planetary gear mechanism having connection one each with thedrive and driven shafts, and in which brake and clutch means arearranged with respect to certain of the elements of the planetary gearmechanisms to provide a plurality of forward drive ratios to the drivenshaft and a reverse drive to the driven shaft.

I propose to achieve the aforesaid objects by providing a transmissioncomprising a first planetary gear mechanism having a first. sun gear,first planet pinion means, and a first ring gear, and a second planetarygear mechanism comprising a second sun gear, second planet pinion meansand a second ring gear. In the preferred embodiment of my inventionherein disclosed the drive shaft for the transmission has drivingconnection with the first ring gear and the driven shaft hasdrivingconnection with the planet arm or carrier of the first planetpinion means. The arrangement further is such that the first ring gearis formed integrally with the second sun gear. In such a relationship ofparts I propose to provide a first brake means selectively operable forholding the first sun gear against rotation for effecting low ratiodrive through the first planetary gear mechanisms and which when thefirst brake means is applied the second planetary gear mechanism idlyrotates without transmitting any torque.

The transmission further embodies a clutch means preferably of the disctype between two of the elements of the first planetary gear mechanismso that when this clutch is actuated with the first brake means referredto being released direct drive in the forward direction is adapted to betransmitted through the first planetary gear mechanism from the drive tothe driven shaft of the transmission. The transmission further comprisesa second brake means associated with the planet arm of the second planetpinion means of the second planetary gear mechanism. which second brakemeans is selectively operable for holding the second planet pinion meansagainst rotation and which when the second brake means is caused to beactuated with the first brake means and the clutch means disengagedeffects reverse drive through the planet pinion means of the firstplanetary gear mechanism to the driven shaft of the transmission.

A preferred feature of the embodiment of my invention herein disclosedresides in an arrangement wherein the first and second planetary gearmechanisms are disposed coaxially and concentrically of a common axis ofthe drive and driven shafts and in which the ring gear of the firstplanetary gear mechanism is formed integrally with the sun gear of thesecond planetary gear mechanism, in which the planet pinion means of thefirst planetary gear mechanism is connected with the ring gear of thesecond planetary gear mechanism, and in which a single clutch means isarranged between the integrally formed sun and ring gears of the firstand second planetary gear mechanism; respectively, on the one hand. andthe connected planet pinion means and 'ring gear of the first and secondplanetary gear mechanism, respectively, on the other hand. I

The above and other objects and advantages of my invention will appearfrom the detail description.

Now in order to acquaint those skilled in the art with the manner ofconstructing and utilizing transmission in accordance with my presentinvention, I shall describe, in connection with the accompanyingdrawings, certain preferred embodiments of my invention.

The single figure of the drawing illustrates diagrammatically atransmission embodyin my present invention.

In the transmission shown in the drawing, a pair of planetary gearmechanisms Pe and P1 are arranged concentrically and co-axially of thecommon axis of the drive and driven shafts He and 320, respectively. Thepair of planetary gear mechanisms comprise the common member 20ctherebetween, and is formed with internal ring gear teeth lilcfor thefirst planetary gear mechanisms P, and external sun gear teeth 230 forthe planetary gear mechanism Pr. The planet carrier member Ilc is formedwith a brake drum portion extending co-axlal of and overlyin the ringgear member 420 of the planetary gear mechanism Pr. A disc clutch Cc isarranged between the ring gear member lie and the planet pinions 21cwith the planet carrier arm of the planetary gear mechanism Po beingconnected with the ring gear member 420 of the Planetary gear mechanismPr. Low ratio drive is adapted to be effected between the drive anddriven shafts by engagement of the brake means lie to hold the sun gear380 of the planetary gear mechanism Pe against rotation with the brakemeans "to and the clutch means C c being disengaged. In order to effectdirect drive from the drive shaft c to the driven shaft 320 the clutchmeans Cc is caused to be engaged to loci: the ring gear member with theplanet pinion means of the planetary gear mechanism P. with, of course.the brake means 920 and llIc being disengaged. In order to effectreverse drive from the drive shaft c to the driven shaft lie the brakemeans me is caused to be actuated with the clutch means Ce and the brakemeans lie disengaged which is effective to hold the planet carrier ofthe planet pinion means of the planetary gear mechanism Pr againstrotation effecting rotation of the ring gear 420 of the latter planetarygear mechanism in a direction opposite the direction of rotation of thecommon ring gear and sun gear element no of the planetary gearmechanisms P. and Pr, respectively, and providing through the planetpinion carrier means of the planetary gear mechanism P8 reverse ratiodrive of the driven shaft 82c.

While I have shown what I consider tobe e preferred embodiment of myinvention, it will be understood that various modifications andrearrangements may be made therein without departing from the spirit andscope of my invention.

I claim:

1. A transmission having co-axially extending drive and driven shaftscomprising, a first planetary gear mechanism disposed co-axially of theaxis of said shafts and having three elements, namely, first sun gear,first planet pinion means and a first ring gear, said first sun gearhaving a first brake drum member associated therewith and spacedlengthwise therefrom along said axis, a second planetary gear mechanismdisposed coaxially of said axis and concentrically of said firstplanetary gear mechanism and having three elements, namely, a second sungear, second planet pinion means, and a second ring gear, said firstring gear and said second sun gear being integral, said second planetpinion means having a second brake drum member disposed co axiallyof'said axis and concentrically of said second ring gear, and clutchmeans disposed co-axially of said axis between said first and secondbrake drum members and associated with said second ring gear and saidfirst planet pinion means, and said first ring gear and said second sungear.

2. A transmission having co-axialiy extending drive and driven shaftscomprising, a first planetary gear mechanism disposed co-axially of theaxis of said shafts and having three elements, namely, a first sun gear,first planet pinion means and a first ring gear, said first sun gearhaving a first brake drum member associated therewith and spacedlengthwise therefrom along said axis, a second planetary gear mechanismdisposed coaxially of said axis and concentrically of said firstplanetary gear mechanism and having three elements, namely, a second sungear. second planet pinion means, and a'second ring gear, said firstring gear and said second sun gear being integral, said first planetpinion means being connected with said second ring gear. said secondplanet pinion means having a second brake drum member disposedco-axially of said axis and concentrically of said second ring gear, andclutch means dis posed co-axially of said axis between said first andsecond brake drum members and associated with said second ring gear andsaid first planet pinion means, and said first ring gear and said secondsun gear.

3. A transmission having co-axially extending drive and driven shaftscomprising a first planetary gear mechanism having three elements.namely, a first sun gear, first planet pinion means, and a first ringgear, said first ring gear being connected with said drive shaft, saidfirst planet pinion means being connected .with said driven shaft, asecond planetary gear mechanism disposed co-axially of the axis of saiddrive and driven shafts and concentrically of said first planetary gearmechanism and having three elements, namely, a second sun gear, secondplanet pinion means, and a second ring gear, said first ring gear andsaid second sun gear being integral, said first planet pinion meansbeing connected with said second ring gear, first brake means associatedwith said first sun gear, second brake means associated with said secondplanet pinion means, and clutch means associated with said second ringgear and said first planet pinion means, and said first ring gear andsaid second sun gear.

4. A transmission having co-axially extending drive and driven shaftscomprising a first planetary gear mechanism having three elements,namely, a first sun gear, first planet pinion means, and a first ringgear, said first ring gear being connected with said drive shaft, saidfirst planet .pinion means being connected with said driven shaft, asecond planetary gear mechanism disposed co-axially of the axis of saiddrive and driven shafts and concentrically of said first planeta y earmechanism and having three elements, namely, a second sun gear, secondplanet pinion means, and a second ring gear, said first ring gear andsaid second sun gear being integral, said first planet pinion meansbeing connected with said second ring gear, and clutch means associatedwith said second ring ear and said first planet pinion means, and saidfirst ring gear and said second sun gear.

5. A transmission having co-axially extending drive and driven shaftscomprising a first planetary gear mechanism having three elements,namely, a first sun gear, first planet pinion means, and a first ringgear, said first ring gear being connected with said drive shaft, saidfirst planet pinion means being connected with said driven shaft, 9.second planetary gear mechanismdisposed co-axially of the axis of saiddrive and driven shafts and concentrically of said first planetary gearmechanism and having three elements, namely, a second sun gear, secondplanet pinion means, and a second ring gear, said first ring gear andsaid second sun gear being integral, said first planet pinion meansbeing connected with said second ring gear, brake means associated withsaid first sun gear, and clutch means associated with said second ringgear and said first planet pinion means, and said first ring gear andsaid second sun gear.

6. A transmission having co-axially extending Y drive anddriven shaftscomprisin a first planetary gear mechanism having three elements,namely, a first sun gear, first planet pinion means, and a first ringgear, said first ring gear being connected with said drive shaft, saidfirstplanet pinion means being connected with said driven shaft, asecond planetary gear mechanism disposed co-axially of the axis of saiddrive and driven shafts and concentrically of said first No referencescited.

